Packaging machine for the production of a packaging having a recess in the packaging cavity edge

ABSTRACT

The present invention relates to a packaging machine having a deep-drawing, filling and sealing station, by way of which a packaging cavity having a recess in the packaging cavity edge is shaped into a plastic film, the packaging cavity is filled with a material for packaging, and subsequently an upper foil is sealed onto the packaging cavity edge in the sealing plane, wherein a cutting tool is integrated into the sealing tool.

The present invention relates to a packaging machine having a swedging, filling and sealing station, by way of which a packaging cavity with a recess in the packaging cavity edge is formed into a plastic film, the packaging cavity is filled with a packaging material and, subsequently in a sealing plane, an upper film is sealed to the packaging cavity edge, a cutting tool being integrated into the sealing tool.

Packaging materials, in particular foodstuffs, are nowadays provided as a rule in plastic packagings which comprise a packaging cavity and an upper film which is sealed on the latter in order to increase their shelf life. Here, it is the aim of the packaging industry to produce packagings of this type with as little material as possible, that is to say with films which are as thin as possible. Machines for producing packagings or packaging cavities are known, for example, from U.S. Pat. No. 3,706,174, U.S. Pat. No. 3,561,057, U.S. Pat. No. 3,815,322, U.S. Pat. No. 3,054,679, U.S. Pat. No. 2,331,472 and EP 0 899 209. In order, nevertheless, to achieve a sufficient stability of the packagings, recesses, such as beads or the like, are integrated into the walls or the edge of the packaging cavity. In particular, in packaging machines which have a swedging, a filling and a sealing station, the problem occurs here, however, that the cover film is not connected to the packaging cavity in the region of the recesses in the packaging cavity edge, which is firstly unseemly and, moreover, leads to the cover film being released more readily from the packaging cavity and being unhygienic because, for example, left over foodstuffs can accumulate between the packaging cavity edge and the upper film.

It was therefore the object of the present invention to provide a packaging machine with a swedging, filling and sealing station, by way of which packaging machine a packaging cavity can be produced which has a recess in the packaging cavity edge and does not have the disadvantages of the prior art.

The object is achieved by way of a packaging machine as claimed in patent claim 1.

It was certainly surprising to a person skilled in the art and not to be expected that it is possible by way of the packaging machine according to the invention to form a packaging cavity into a plastic film, to fill this packaging cavity with a packaging material and subsequently to seal it with a cover film in such a way that the latter does not have any regions which are not sealed in an undesired manner. As a result, the packaging is very much more seemly than similar packagings which have been produced according to the prior art and, moreover, it is precluded that the cover film is released unintentionally from the packaging cavity and that foodstuff accumulates between the cover film and the packaging cavity edge.

According to the invention, the packaging machine has a swedging, filling and sealing station. In the swedging station, a packaging cavity is swedged into a flat film by swedging into a predefined shape, for example by way of a punch, excess pressure and/or vacuum. According to the invention, this packaging cavity has a recess in its vertical edge, in order for it to be possible to design the packaging over all, but in particular the edge region, to be more stable. During swedging, this recess is formed into the plastic film. The packaging cavity which is produced in this way is then filled with a packaging material, in particular a foodstuff.

Afterward, the filed packaging cavity is covered with the upper film and sealed in the edge region.

According to the invention, a cutting tool is integrated into the sealing tool which is required for this purpose, by way of which cutting tool the upper film of the respective packaging is merely severed from the plastic film upper web.

The cutting tool is preferably arranged in the transition region between the sealing plane and the recess. It is further preferred for the cutting tool to be arranged on the circumference of the sealing tool. Both embodiments have the advantage that the cover film is cut off immediately at the circumference of the sealed region, with the result that there is no unsealed region between the edge of the seal and the recess, which unsealed region can lead to the upper film being detached more easily or left over foodstuffs accumulating in it which represent a hygiene problem. Each cutting tool is preferably driven separately.

Sealing preferably takes place before, after or at the same time as cutting of the upper film.

It is preferred, furthermore, for the packaging cavity to be produced in such a way that the sealing plane lies above the transport plane of the plastic film web, from which the packaging cavity is produced. This embodiment of the present invention has the advantage that, the subsequent sealing process, the sealing plane is more readily accessible for the sealing tool and the surface can be severed by the cutting tool, without the packaging cavity being damaged in the process.

In the following text, the invention will be explained using FIGS. 1 to 3 c. These explanations are merely by way of example and do not restrict the general inventive concept.

FIG. 1 shows the packaging machine according to the invention.

FIGS. 2 a to 2 b show the swedging station of the packaging machine according to the invention.

FIG. 2 c shows a packaging cavity which is produced in the swedging station according to FIGS. 2 a to 2 b.

FIGS. 3 a to 3 c show the evacuation, sealing and cutting of the upper film.

FIG. 1 shows the packaging machine 1 according to the invention which has a swedging station 2, a filling station 7 and a sealing station 19. A plastic film web 8, what is known as the lower web, is preferably transported, cyclically along the packaging machine according to the invention from the right to the left in what is known as the film plane. The packaging cavities 6 are formed into the film web 8 in the swedging station 2 which comprises an upper mold 3 and a lower mold 4 which has the shape of the packaging cavity which is to be produced. The lower mold 4 is arranged on an elevating platform 5 which can be moved vertically, as symbolized by the double arrow. In the further course of the packaging machine, the packaging cavities are then filled with the packaging material 16 in the filling station 7. In the subsequent sealing station 19 which likewise comprises an upper mold 12 and a vertically movable lower mold 11, an upper film is sealed onto the packaging cavity and, as explained using FIGS. 3 a to 3 c, the respective packaging is severed from the upper film web. In the further course of the packaging machine, the finished packagings are also separated from the lower film 8.

FIG. 2 a shows details of the forming station 2. The upper mold 3 has, inter alia, a clamping frame 20 and a forming punch 17, while the lower mold 4 comprises substantially the swedging mold. The plastic film 8 is transported cyclically along what is known as the film plane which extends perpendicularly with respect to the paper plane between the components of the upper mold 2 and the lower mold 4.

FIG. 2 b shows the deformation of the plastic film 8 into the respective packaging cavity which has been heated to the melting temperature before the deformation. First of all, the plastic film 8 is clamped between the clamping frame 20 and the lower mold 4 and in the process the sealing plane 13 and therefore the recess 9 are formed into the plastic film. A person skilled in the art sees that the recess 9 is situated in the film plane, that is to say in the transport plane of the plastic film 8, while the sealing plane 13 extends upward out of the film plane. After the plastic film 8 has been clamped fixedly, the packaging cavity 6 is formed into the film web by way of a forming punch 17 which can be raised and lowered, as shown by the double arrow. Optionally, the deformation is reinforced by a vacuum which prevails in the region of the lower mold or by an excess pressure which prevails in the upper mold.

FIG. 2 c shows the packaging cavity 6 which results from the swedging operation according to FIGS. 2 a and 2 b. In its edge region 18, this packaging cavity has a sealing plane 13 which is adjoined circumferentially by a recess 9.

FIGS. 3 a to 3 c show the sealing of the upper film 14 to the packaging cavity 6. The sealing station 10 has an upper mold 12 which comprises substantially a sealing frame 10 and a knife 15 which extends over the entire circumference of the sealing frame 10. As will be shown later, the upper film 14 is severed before, after or during the sealing by way of the knife 15. Both the sealing frame 13 and the knife 15 can be lowered and raised, the respective movement taking place substantially independently of one another. Said movement can be effected, for example, by a drive, the sealing frame being arranged resiliently on the drive and, as soon as the sealing frame bears against a counterpart (not shown) with a sufficient pressure, the knife 15 being pressed in the direction of the upper web 14 and severing it. Here, the edge of the sealing plane interacts with the knife.

FIG. 3 a shows first of all the evacuation or the gas exchange with n the packaging cavity. This takes place before the upper film 14 is placed onto the packaging cavity 6.

After the evacuation or the gas exchange has been concluded, the sealing frame is moved downward, as shown in FIG. 3 b, in order to carry out the sealing of the upper film 14 to the packaging cavity 6. This takes place as a rule by the influence of temperature and pressure, by the preheated sealing frame being pressed against the packaging cavity 6. A person skilled in the art knows that a sealing frame which serves as abutment for the sealing frame 10 is also arranged in the region of the packaging cavity 6.

The upper film can also optionally be severed immediately before sealing.

As soon as the upper film 14 has been sealed to the packaging cavity 6 or at the same time, the knife is moved downward, as shown by the arrow in FIG. 3 c, and severs the upper film directly in the region of the recess in the packaging cavity edge.

As a result of the fact that the knife 15 severs the upper film in the region of the recess and the sealing frame 10 welds the upper film to the packaging cavity completely in the sealing plane 13 in the region of the sealing plane, no unsealed regions at all occur in the region of the sealing plane, in which unsealed regions pockets, for example, can form, in which left over foodstuffs accumulate.

List of Designations

-   1 Packaging machine -   2 Swedging station -   3 Upper mold of the swedging station -   4 Lower mold of the swedging station -   5 Elevating platform of the swedging station -   6 Packaging cavity -   7 Filling station -   8 Lower film plastic web -   9 Recess in the packaging cavity edge -   10 Sealing frame -   11 Lower mold of the sealing station -   12 Upper mold of the sealing station -   13 Sealing plane -   14 Upper film -   15 Cutting tool in the sealing station -   16 Packaging material -   17 Forming punch -   18 Packaging cavity edge -   19 Sealing station -   20 Clamping frame 

1. A packaging machine having a swedging, filling and sealing station, by way of which a packaging cavity with a recess in the packaging cavity edge is formed into a plastic film, the packaging cavity is filled with a packaging material and, subsequently in the sealing plane, an upper film is sealed to the packaging cavity edge, sealing being effected under the influence of pressure and temperature and a cutting tool being integrated into the sealing tool, characterized in that the sealing plane lies above the transport plane of the plastic film web from which the packaging cavity is produced, and in that the cutting tool severs the upper film of the respective packaging from the plastic film upper web.
 2. The packaging machine as claimed in claim 1, characterized in that the cutting tool is arranged in the transition region between the sealing plane and the recess.
 3. The packaging machine as claimed in claim 1, characterized in that the cutting tool is arranged on the circumference of the sealing tool.
 4. The packaging machine as claimed in claim 2, characterized in that the cutting tool is arranged on the circumference of the sealing tool. 